Line branching printed circuit board for a computer numerical controller

Abstract

A line branching printed circuit board for a computer numerical controller designed to branch an input/output signal line connecting a computer numerical controller and a numerically controlled machine tool, and comprising a first circuit board connector (20A) coupled to a junction connector to which input/output signal lines from the computer numerical controller are connected, and a plurality of second circuit board connectors (21aA, 21bA and 21cA) which are all coupled to the junction connectors to which the input/output signal lines to the numerically controlled machine tool are connected, and having pins pattern-connected to the pins of the first circuit board connector. There is further provided a third circuit board connector (22A) having pins pattern-connected to the spare pins of the first circuit board connector (20A) and the spare pins of the plurality of the second circuit board connectors (21aA, 21bA and 21cA). A connection changing connector (22B) is attached to the third circuit board connector (22A), to determine the connection of the pins of the third circuit board connector, and by changing the connection of the connection changing connector, the connection between the computer numerical controller and the numerically controlled machine tool can be easily changed.

What is claimed is: 
     
       1. A line branching printed circuit board for a computer numerical controller, which branches input/output signal lines between the computer numerical controller and a numerically controlled machine tool, comprising a first circuit board connector coupled to a junction connector to which the input/output signal lines from the computer numerical controller are connected,   a plurality of second circuit board connectors which are coupled to junction connectors to which the input/output signal lines to said numerically controlled machine tool are connected, said plurality of second circuit board connectors having pins being directly pattern-connected to pins of said first circuit board connector,   a third circuit board connector having pins pattern-connected to spare pins of said first circuit board connector and spare pins of said plurality of second circuit board connectors, and   a connection changing connector attached to said third circuit board connector and having means for determining the connection of the pins of said third circuit board connector to each other, thereby determining the connection of the spare pins of said first circuit board connector to the spare pins of said plurality of second circuit board connectors.   
     
     
       2. The line branching printed circuit board for a computer numerical controller according to claim 1, wherein said connection changing connector uses a wire wrapping method for connections between the junction terminals. 
     
     
       3. The line branching printed circuit board for a computer numerical controller according to claim 1, wherein said connection changing connector uses patterns on a printed circuit board for connecting the junction terminals. 
     
     
       4. The line branching printed circuit board for a computer numerical controller according to claim 1, wherein said connection changing connector uses soldered connecting wires for connecting the junction terminals. 
     
     
       5. The line branching printed circuit board for a computer numerical controller according to claim 1, wherein said connection changing connector includes a connecting wire arranged to operatively connect the pins of said third circuit board connector. 
     
     
       6. The line branching printed circuit board for a computer numerical controller according to claim 5, wherein said connecting wire is soldered to junction terminals of said connection changing connector. 
     
     
       7. The line branching printed circuit board for a computer numerical controller according to claim 5, wherein said connecting wire is wrap connected to junction terminals of said connection changing connector. 
     
     
       8. The line branching printed circuit board for a computer numerical controller according to claim 1, wherein said connection changing connector includes a printed circuit board having patterns arranged to operatively connect the pins of said third circuit board.